The present invention relates to a vehicle area detecting apparatus and a vehicle area determining method for detecting an area of a vehicle in accordance with an image from a charge coupled device (CCD) installed in a vehicle.
Various methods have been proposed to detect an area of a vehicle in accordance with an image of the vehicle obtained by an imaging device such as a CCD camera mounted on a vehicle such as a car.
An area of a vehicle has been commonly determined, for example, as follows.
(1) For differentiated images, i.e., edge images of an image in front of a vehicle, there are conducted such operations as binarization, labeling, feature extraction, and pattern template matching.
(2) A particular zone of the overall front image is assumed as a road surface. A degree of gradation of the road surface is compared with that of an image of a zone in which the vehicle is brought into contact with the road surface.
However, the template matching in the former method (1) is attended with a problem. Namely, the target items have various contours and the obtained images vary depending on weather conditions as well as environmental conditions, for example, an image produced in the daytime is different from that attained in the nighttime. This makes it difficult to produce a template generally applicable to various cases. With the existing templates, it is consequently difficult to appropriately determine a vehicle area by the template matching. The latter method (2) using the comparison of the degree of gradation of the road surface is also attended with a problem. Due to various shadows on the road surface, the overall road surface is not uniform and hence the degree of gradation cannot be easily determined for the overall road surface. Even when a zone of the road surface is used to obtain a mean value of degree of gradation for the degree of gradation of the overall road surface, it can be considered that the obtained degree of gradation is different from that of the road surface in the vicinity of a vehicle candidate area as a target. Consequently, it is difficult to appropriately determine the vehicle area.
It is therefore an object of the present invention to provide a vehicle area detecting apparatus and a vehicle area determining method capable of more correctly identifying a vehicle area in a simple procedure.
In accordance with the present invention, there is provided a vehicle area detecting apparatus comprising imaging means mounted on a vehicle for producing an image of an object and vehicle area detecting means mounted on the vehicle for detecting a vehicle area including a vehicle in the image produced by the imaging means. The vehicle area detecting means detects the vehicle area when the vehicle area includes an image for which either one of the conditions of a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a degree of variance in the degree of gradation in the image of the area, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area exceeds a predetermined threshold value.
In accordance with the present invention, there is provided a vehicle area detecting apparatus comprising imaging means mounted on a vehicle for producing an image of an object and vehicle area detecting means mounted on the vehicle for detecting a vehicle area including a vehicle in the image produced by the imaging means. The vehicle area detecting means detects the vehicle area when the vehicle area includes an image for which two of the conditions of a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a degree of variance in the degree of gradation in the image of the area, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area exceed respective predetermined threshold values.
In accordance with the present invention, there is provided a vehicle area detecting apparatus comprising imaging means mounted on a vehicle for producing an image of an object and vehicle area detecting means mounted on the vehicle for detecting a vehicle area including a vehicle in the image produced by the imaging means. The vehicle area detecting means detects the vehicle area when the vehicle area includes an image for which a degree of horizontal symmetry with respect to a degree of gradation in the image of the area is larger than a predetermined threshold value, a degree of variance in the degree of gradation in the image of the area is larger than a predetermined threshold value, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area is larger than a predetermined threshold value.
In accordance with the present invention, there is provided a vehicle area detecting apparatus comprising imaging means mounted on a vehicle for producing an image of an object and vehicle area detecting means mounted on the vehicle for detecting a vehicle area including a vehicle in the image produced by the imaging means. The vehicle area detecting means detects the vehicle area as an area at a position substantially equal to that of the vehicle area when the area satisfies up to this point a predetermined number of times either one of a condition for a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a condition for a degree of variance in the degree of gradation in the image of the area, and a condition for a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area.
In accordance with the present invention, there is provided a vehicle area detecting apparatus comprising imaging means mounted on a vehicle for producing an image of an object and vehicle area detecting means mounted on the vehicle for detecting a vehicle area including a vehicle in the image produced by the imaging means. The vehicle area detecting means detects the vehicle area as an area at a position substantially equal to that of the vehicle area when the area satisfies up to this point a predetermined number of times two of the conditions for a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a degree of variance in the degree of gradation in the image of the area, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area.
In accordance with the present invention, there is provided a vehicle area detecting apparatus comprising imaging means mounted on a vehicle for producing an image of an object; and vehicle area detecting means mounted on the vehicle for detecting a vehicle area including a vehicle in the image produced by the imaging means. The vehicle area detecting means detects the vehicle area as an area at a position substantially equal to that of the vehicle area when the area satisfies up to this point a predetermined number of times the conditions for a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a degree of variance in the degree of gradation in the image of the area, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area.
In accordance with the present invention, there is provided a vehicle area detecting apparatus for detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The apparatus includes horizontal symmetry evaluating means for evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, variance evaluating means for evaluating a degree of variance in the degree of gradation in the image of the area, mean gradation evaluating means for evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area, and area determining means for determining a vehicle candidate area as the vehicle area when either one of results of evaluation from the symmetry evaluating means, the variance evaluating means, and the mean gradation evaluating means exceeds a predetermined threshold value.
In accordance with the present invention, there is provided a vehicle area detecting apparatus for detecting a vehicle area in a vehicle candidate area having a probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle comprising horizontal symmetry evaluating means for evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, variance evaluating means for evaluating a degree of variance in the degree of gradation in the image of the area, mean gradation evaluating means for evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area and area determining means for determining a vehicle candidate area as the vehicle area when two of the results of evaluation from the symmetry evaluating means, the variance evaluating means, and the mean gradation evaluating means exceed respective predetermined threshold values.
In accordance with the present invention, there is provided a vehicle area detecting apparatus for detecting a vehicle area in a vehicle candidate area having a probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle comprising horizontal symmetry evaluating means for evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, variance evaluating means for evaluating a degree of variance in the degree of gradation in the image of the area, mean gradation evaluating means for evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area and area determining means for determining a vehicle candidate area as the vehicle area when the results of evaluation from the symmetry evaluating means, the variance evaluating means, and the mean gradation evaluating means exceed respective predetermined threshold values.
In accordance with the present invention, there is provided a vehicle area detecting apparatus for detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The apparatus includes horizontal symmetry evaluating means for evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, variance evaluating means for evaluating a degree of variance in the degree of gradation in the image of the area, mean gradation evaluating means for evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area, area determining means for determining a vehicle candidate area as the vehicle area when either one of the results of evaluation from the symmetry evaluating means, the variance evaluating means, and the mean gradation evaluating means exceeds a predetermined threshold value and area evaluating means for detecting a vehicle candidate area at a position substantially equal to that of a vehicle candidate area as the vehicle area when an event in which either one of the results of evaluation from the symmetry evaluating means, the variance evaluating means, and the mean gradation evaluating means exceeds a predetermined threshold value is detected up to this point a predetermined number of times for the vehicle candidate area by the area determining means.
In accordance with the present invention, there is provided a vehicle area detecting apparatus for detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The apparatus includes horizontal symmetry evaluating means for evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, variance evaluating means for evaluating a degree of variance in the degree of gradation in the image of the area, mean gradation evaluating means for evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area, area determining means for determining a vehicle candidate area as the vehicle area when two of the results of evaluation from the symmetry evaluating means, the variance evaluating means, and the mean gradation evaluating means exceed respective predetermined threshold values, and area determining means for detecting a vehicle candidate area at a position substantially equal to that of a vehicle candidate area as the vehicle area when an event in which two of the results of evaluation from the symmetry evaluating means, the variance evaluating means, and the mean gradation evaluating means exceed respective predetermined threshold values is detected up to this point a predetermined number of times for the vehicle candidate area by the area determining means.
In accordance with the present invention, there is provided a vehicle area detecting apparatus for detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The apparatus includes horizontal symmetry evaluating means for evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, variance evaluating means for evaluating a degree of variance in the degree of gradation in the image of the area, mean gradation evaluating means for evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area, area determining means for determining a vehicle candidate area as the vehicle area when the results of evaluation from the symmetry evaluating means, the variance evaluating means, and the mean gradation evaluating means exceed respective predetermined threshold values, and area determining means for detecting a vehicle candidate area at a position substantially equal to that of a vehicle candidate area as the vehicle area when an event in which the results of evaluation from the symmetry evaluating means, the variance evaluating means, and the mean gradation evaluating means exceed respective predetermined threshold values is detected up to this point a predetermined number of times for the vehicle candidate area by the area determining means.
In accordance with the present invention, there is provided a vehicle area detecting method, comprising the steps of imaging an image of an object and detecting a vehicle area including a vehicle in the image produced by the imaging step. The vehicle area detecting step includes the step of detecting the vehicle area when the vehicle area includes an image for which either one of the conditions of a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a degree of variance in the degree of gradation in the image of the area, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area exceeds a predetermined threshold value.
In accordance with the present invention, there is provided a vehicle area detecting method, comprising the steps of imaging an image of an object and detecting a vehicle area including a vehicle in the image produced by the imaging step. The vehicle area detecting step includes the step of detecting the vehicle area when the vehicle area includes an image for which two of the conditions of a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a degree of variance in the degree of gradation in the image of the area, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area exceed respective predetermined threshold values.
In accordance with the present invention, there is provided a vehicle area detecting method, comprising the steps of imaging an image of an object and detecting a vehicle area including a vehicle in the image produced by the imaging step. The vehicle area detecting step includes the step of detecting the vehicle area when the vehicle area includes an image for which a degree of horizontal symmetry with respect to a degree of gradation in the image of the area is larger than a predetermined threshold value, a degree of variance in the degree of gradation in the image of the area is larger than a predetermined threshold value, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area is larger than a predetermined threshold value.
In accordance with the present invention, there is provided a vehicle area detecting method, comprising the steps of imaging an image of an object and detecting a vehicle area including a vehicle in the image produced by the imaging step. The vehicle area detecting step includes the step of detecting the vehicle area as an area at a position substantially equal to that of the vehicle area when the area satisfies up to this point a predetermined number of times either one of a condition for a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a condition for a degree of variance in the degree of gradation in the image of the area, and a condition for a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area.
In accordance with the present invention, there is provided a vehicle area detecting method, comprising the steps of imaging an image of an object and detecting a vehicle area including a vehicle in the image produced by the imaging step. The vehicle area detecting step includes the step of detecting the vehicle area as an area at a position substantially equal to that of the vehicle area when the area satisfies up to this point a predetermined number of times two of the conditions of a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a degree of variance in the degree of gradation in the image of the area, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area.
In accordance with the present invention, there is provided a vehicle area detecting method, comprising the steps of imaging an image of an object and detecting a vehicle area including a vehicle in the image produced by the imaging means. The vehicle area detecting step includes the step of detecting the vehicle area as an area at a position substantially equal to that of the vehicle area when the area satisfies up to this point a predetermined number of times the conditions for a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a degree of variance in the degree of gradation in the image of the area, and a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area.
In accordance with the present invention, there is provided a vehicle area detecting method of detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The method includes a horizontal symmetry evaluating step of evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a variance evaluating step of evaluating a degree of variance in the degree of gradation in the image of the area, a mean gradation evaluating step of evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area, and an area determining step of determining a vehicle candidate area as the vehicle area when either one of the results of evaluation from the symmetry evaluating step, the variance evaluating step, and the mean gradation evaluating step exceeds a predetermined threshold value.
In accordance with the present invention, there is provided a vehicle area detecting method of detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The method includes a horizontal symmetry evaluating step of evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a variance evaluating step of evaluating a degree of variance in the degree of gradation in the image of the area, a mean gradation evaluating step of evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area and an area determining step of determining a vehicle candidate area as the vehicle area when two of the results of evaluation from the symmetry evaluating step, the variance evaluating step, and the mean gradation evaluating step exceed respective predetermined threshold values.
In accordance with the present invention, there is provided a vehicle area detecting method of detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The method includes a horizontal symmetry evaluating step of evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a variance evaluating step of evaluating a degree of variance in the degree of gradation in the image of the area, a mean gradation evaluating step of evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area and an area determining step of determining a vehicle candidate area as the vehicle area when the results of evaluation from the symmetry evaluating step, the variance evaluating step, and the mean gradation evaluating step exceed respective predetermined threshold values.
In accordance with the present invention, there is provided a vehicle area detecting method of detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The method includes a horizontal symmetry evaluating step of evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a variance evaluating step of evaluating a degree of variance in the degree of gradation in the image of the area, a mean gradation evaluating step of evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area, an area determining step of determining a vehicle candidate area as the vehicle area when either one of the results of evaluation from the symmetry evaluating step, the variance evaluating step, and the mean gradation evaluating step exceeds a predetermined threshold value, and an area evaluating step for detecting a vehicle candidate area at a position substantially equal to that of a vehicle candidate area as the vehicle area when an event in which either one of the results of evaluation from the symmetry evaluating step, the variance evaluating step, and the mean gradation evaluating step exceeds a predetermined threshold value is detected up to this point a predetermined number of times for the vehicle candidate area by the area determining step.
In accordance with the present invention, there is provided a vehicle area detecting method of detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The method includes a horizontal symmetry evaluating step of evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a variance evaluating step of evaluating a degree of variance in the degree of gradation in the image of the area, a mean gradation evaluating step of evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area, an area determining step of determining a vehicle candidate area as the vehicle area when two of the results of evaluation from the symmetry evaluating step, the variance evaluating step, and the mean gradation evaluating step exceed respective predetermined threshold values, and an area evaluating step for detecting a vehicle candidate area at a position substantially equal to that of a vehicle candidate area as the vehicle area when an event in which two of the results of evaluation from the symmetry evaluating step, the variance evaluating step, and the mean gradation evaluating step exceed respective predetermined threshold values is detected up to this point a predetermined number of times for the vehicle candidate area by the area determining means.
In accordance with the present invention, there is provided a vehicle area detecting method of detecting a vehicle area in a vehicle candidate area having a high probability of existence of a vehicle in an image produced by imaging means mounted on a vehicle. The method includes a horizontal symmetry evaluating step of evaluating a degree of horizontal symmetry with respect to a degree of gradation in the image of the area, a variance evaluating step of evaluating a degree of variance in the degree of gradation in the image of the area, a mean gradation evaluating step of evaluating a difference in the degree of gradation of an image between a lower area of a vehicle candidate area and an area in the proximity of a lower edge of the candidate area, an area determining step of determining a vehicle candidate area as the vehicle area when the results of evaluation from the symmetry evaluating step, the variance evaluating step, and the mean gradation evaluating step exceed respective predetermined threshold values, and an area evaluating step for detecting a vehicle candidate area at a position substantially equal to that of a vehicle candidate area as the vehicle area when an event in which the results of evaluation from the symmetry evaluating step, the variance evaluating step, and the mean gradation evaluating step exceed respective predetermined threshold values is detected up to this point a predetermined number of times for the vehicle candidate area by the area determining means.